The present invention relates to a vehicle seat having two seat parts, namely a seat bottom and a backrest, at least one of the seat parts comprising a ventilation system. The invention further relates to a method for comfort ventilation of a vehicle seat.
In the automotive industry, sitting comfort and driving comfort is an important field. Special problems arise in a warm and sunny climate, as the interior of a parked vehicle can reach very high temperatures. It goes without saying that this affects the temperature of the car seats, which can get very hot, in particular if the covering is dark. As a consequence, a person entering the vehicle may burn himself when sitting down on the vehicle seat. Moreover, there is further discomfort at an initial stage, since the driver is probably perspiring after having been outside in the hot climate. Thus, it is important to lead away the moisture from the surface of the seat. At the same time, the draught must not be too strong as this may have a detrimental effect on the driver""s/the passenger""s health.
A number of devices of the type mentioned by way of introduction are already known. For instance, mention can be made of devices comprising a plurality of fans which are arranged in the seat and distributed over a large surface. This is a very expensive solution, which is sensitive to strain, in particular due to the control electronics which has to be integrated in the seat bottom to control the fans. Other solutions comprise a number of sensors and the like in the seat bottom to control the power of the fans and the like, but these systems also require electronics integrated in the seat bottom and are thus sensitive.
Therefore, it is an object of the invention to provide a ventilation system for a car seat, said system obviating the above-mentioned problems and having a simple design, at the same time as the system does not have a detrimental effect on the driver""s/passenger""s health.
According to the invention, the above-mentioned object is achieved by means of a ventilation system, which comprises a network of ducts, a subset of these ducts being at least partially closable with a view to permitting redirecting of air flows in the seat part. This permits a change of the cooling and moisture-removing capability of the seat cushion, without any direct regulation by means of fans and the like.
Preferably, said network of ducts comprises ducts extending substantially in the planar direction of the seat part as well as substantially in the thickness direction of the seat part, which permits a satisfactory removal of heat (ducts in the thickness direction) and moisture (ducts in the planar direction).
Furthermore, said network of ducts suitably comprises one or more branch ducts extending substantially in the thickness direction and through substantially the entire seat part. These ducts are suitably located centrally in the seat.
Said network of ducts further comprises an additional number of joint ducts which extend substantially in the thickness direction of the seat part and which constitute said at least partially closable ducts. These joint ducts end at the sitting surface of the seat, and the orifices of these joint ducts can be spread over the sitting surface in such manner that a satisfactory and quick cooling is provided. Moreover, the partially closable joint ducts are connected, in their ends facing away from the sitting surface of the seat part, with at least one of said branch ducts via connection ducts extending substantially in the planar direction. As a result, air can be conveyed from the upper side of the seat, via branch ducts and the closable joint ducts, to be gathered in the branch ducts for a common discharge of all air through the same.
Suitably, a fan element is also arranged in fluid contact with said branch ducts on the side of the seat part opposite to the sitting surface of the seat part. This fan element is suitably of a one-way type and exhausts air from the sitting surface of the seat part through said network of ducts and to the opposite side of the seat part. This arrangement permits an efficient flow of air through the network of ducts and provides cooling over a large surface of the seat by means of only one fan element thanks to the above-mentioned distribution of the orifices of the joint ducts over the sitting surface.
Preferably, the network comprises a number of ducts distributed at least along the sitting surface of the seat part, one end of these ducts ending in at least one of said branch ducts, the ends of said at least partially closable joint ducts facing the sitting surface of the seat part ending in one of said surface ducts. Furthermore, the seat part suitably has a perforated or otherwise permeable surface layer extending over substantially the entire sitting surface of the seat part. As a result, air as well as moisture, for instance sweat, can penetrate the surface layer of the seat part and into the surface ducts, whereupon air and moisture are conveyed to one of the branch ducts.
Moreover, the seat part is suitably made of cellular plastic or the like, the area of said surface ducts being made of a rigid material and the area of said at least partially closable joint ducts and said connection ducts being made of a comparatively softer material, said connection ducts being at least partially compressed when applying a load to the seat part. This compression results in the above-mentioned closing capability of a subset of the ducts and stops at least partially the air flow in the same. This closability can also be provided by arranging valve means in said at least partially closable joint ducts.
The above-mentioned objects are also achieved by a method for comfort ventilation comprising the steps of starting by remote control a fan element which is arranged in connection with the seat part, generating by means of said fan element (6) a flow of air through a network of ducts (2, 3, 4, 5) which is arranged in the seat part and whose orifices are distributed over the sitting surface, and closing at least partially a subset of said ducts, and thus redirecting the air flow through the seat part when applying a load to the seat part. Thus, this method makes it possible to pre-cool the seat part before the driver/passenger sits down in the vehicle, after which a change takes place from a cooling phase to a moisture-removing phase the moment the driver/passenger sits down in the vehicle.
Suitably, the step of completely or partially closing certain ducts is carried out by compressing the seat part when applying a load, thereby causing mechanical changes in the structure of the seat bottom. Preferably, the step of at least partially closing a subset of ducts is carried out by compressing connection ducts arranged in the seat part when applying a load. This is a purely mechanical and very simple structure, which eliminates the need of sensors and the like for this purpose. In addition, it is ensured that the transition between the various phases takes place the moment the driver/passenger first applies a load to the seat part.
Furthermore, the step of generating by means of said fan element a flow of air through a network of ducts arranged in the seat part consists in exhausting air from the sitting surface of the seat part, through said network of ducts, whose orifices are distributed over the sitting surface, to the opposite side of the seat part. Preferably, the method also comprises the step of varying the speed of the fan after the closing step to generate a comfortable air flow through the seat part.
Finally, the step of starting the fan element by remote control can be carried out by the start function of the fan being connected, for instance, to the remote key of the vehicle, the vehicle door handle, alarm device or the like, depending of what is considered to be suitable.